NATS - the National Air Traffic Service - has released a short video entitled 'A Day Over the UK'
which features a simulation of the days air traffic in our sky.
Watch the morning rush of flights from the US to Europe, helicopter flights to the oilfields, military exercises and general traffic stacking above major airports.
There are several more of its like on their site, including 'UK 24' and 'North Atlantic Skies'.
The above link is from the vimeo site as it gave the biggest display, but also on the NATS site and YouTube.